Tank Smell

[gthompson1968]

For the past few days... when I lift the canopy to my tank it smells fishy. However, when I extract a cup of the water and smell it I do not smell anything. I have tested the Ammonia and Nitrite levels and everything seems to be just fine. It does not smell like rotten eggs. The odor reminds me of when I had to drain my tank to move and the smell that the substrate had when I was scooping it out. Maybe my nose is just very sensitive this past week.
The filtration on my tank consists of a wet dry system and an external Eheim canister filter. My Eheim has Chemi-Pure and Purigen in it. I swapped these out a couple of months ago so they should still be in good shape.
Any ideas?

 

[chrismilano]

whats in the tank. How big?
tap water?
check for dead guys under rocks? Dead feeders, etc.

 

[clowning68]

Algae growth will contribute to fishy smell, so if you have algae or lots of rock then that might be whats going on. As long as the parameters are good then dont worry.

 

[krishj39]

you don't mention that you have a protein skimmer, so I wonder if your problem is that you have a layer of protiens on the surface that are causing the smell. If you can't shake the smell, try some surface agitation, or get a skimmer. Or, it could be something else entirely, this is just a thought. But, I do think that no matter what the cause, a skimmer would cut down on the smell.
kris

 

[twoods71]

What is your nitrate level?
A high nitrate level can be an indication of a build up of other organics causing the smell.